Terror bass 500 and OBC115

[Stub Mandrel]

Fwiw I have a 500W OBT into an 800w rated cab. I tried turning it up loud, but it got scary... rather like doing the ton downhill in my old Morris Marina.

[CJPJ]

2 minutes ago, Stub Mandrel said:

 

Yes, the 4/8 switch changes the output voltage level to give 500w into either impedance.

We crossed in the post 🙂 . That's not what the Orange website suggests - 

 

[Downunderwonder]

30 minutes ago, Lozz196 said:

I’m sorry I don’t understand why 165 watts into a 300 watt cab would have destroyed it.

Because low end peaks cause very high speaker excursions with much higher voltage for a short time. This can be indicated by the ''burst power'' rating of the amp which some makers use as the number on the front.

 

Farting sounds are hard to hear at the loud end of operating, particularly with distorted guitars accompanying. They may even sound 'cool' in that context.

[Stub Mandrel]

2 hours ago, CJPJ said:

We crossed in the post 🙂 . That's not what the Orange website suggests - 

 

 

Seems you may be right. The new amp behaves differently and the switch just adds protection into 4R.

 

Glad I got a 4 ohm 2x12. Otherwise i would have to buy another 🤣

[CJPJ]

7 hours ago, Stub Mandrel said:

The new amp behaves differently and the switch just adds protection into 4R.

 

 

Yeah. I'm sure the my Mk1 gave the full power out at 8ohm.

 

[CJPJ]

Hmmm. This thread has got me thinking. I wonder if I should get 2 x OCB112 to pair with my OTB. It'd 4ohm both connected with plently of headroom in the cabs but if I wanted to just practice then one cab would be fine and the 250w at 8ohm would sit nicely in the single cab range. They are only 12kg each as well . . . . 

[Clarky]

There's a suspiciously cheap new OBC112 on eBay (£285). Not sure I trust seller which has some positive feedback but only as a buyer yet sounds like a business? Anyhow, someone might fancy the gamble (has eBay money back guarantee) https://www.ebay.co.uk/itm/313953081226?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=0lixvzoptsy&sssrc=2349624&ssuid=eqlPJw_SSty&var=&widget_ver=artemis&media=COPY

[BassmanPaul]

Just remember that using a bass a rule of thumb could be to derate the cabinets power rating by 50%.

[CJPJ]

1 hour ago, Clarky said:

There's a suspiciously cheap new OBC112 on eBay (£285). 

Cheers. Does look like a random seller - esp. as 'new'. If I was only getting the one I might look at it but as I would get two I'd probaby buy together (and be able to return together if needed 🙂 )

[CJPJ]

22 minutes ago, BassmanPaul said:

Just remember that using a bass a rule of thumb could be to derate the cabinets power rating by 50%.

How do you mean? 2 x 400 watt 8ohm put through a 500w 4ohm amp should still give the 500w and have headroom no? 

[Downunderwonder]

19 minutes ago, CJPJ said:

How do you mean? 2 x 400 watt 8ohm put through a 500w 4ohm amp should still give the 500w and have headroom no? 

Depends what you mean by headroom.

 

I doubt there is anything special about the 12 in those cabs. Two should get very loud and run out of puff somewhere around the same time as the amp. Trouble comes if there's enough poke left in the amp to hurt the cabs.

 

No way of telling except to try but I expect if you dialed in a bit of low end boost and no HPF you could fart the cabs. 

[CJPJ]

That’s always my fear and the reason why I’d originally thought of getting a Barefaced big twin or similar. I just really like the aesthetics of the Orange kit 🙄 and want them to work with the OTB. I’m just not sure how much I want to go through the faff of returning them 

[Downunderwonder]

46 minutes ago, CJPJ said:

That’s always my fear and the reason why I’d originally thought of getting a Barefaced big twin or similar. I just really like the aesthetics of the Orange kit 🙄 and want them to work with the OTB. I’m just not sure how much I want to go through the faff of returning them 

I think if you put a big twin under it the aesthetic would be the last thing on your mind. You could always demo one and then special order a new one in Orange orange.

[CJPJ]

9 minutes ago, Downunderwonder said:

special order a new one in Orange orange.

Nice idea! I hadn’t thought about that. 

[Downunderwonder]

4 hours ago, CJPJ said:

Orange

The other consideration is the sensitivity, aka dB per watt. For twin cabs wired parallel you add 6dB to the quoted sensitivity spec, hoping like hell it is honestly applying to the 70 to 140hz octave. Then you add 3dB for each doubling of 1w they can handle before power compression kicks in. 1 2 4 8 16 32 64 128...256 is stretching a little but what the heck, 8x. Add 24+6 = +30dB to the number Orange gives for 1 cab. Might pay to do some research on their veracity.

 

The Barefaced 12'' driver isn't so sensitive but eats up wattage. I believe they claim 97dB honest broadband sensitivity and 512W isn't a big stretch when rated to 600W. 97 plus 27 is 124dB. Barefaced come to 127dB so they are not allowing for power compression and even cribbing some extra mathematically speaking when they call it 800w in the Big Baby. Tbf they do call it Max ~dB which I guess it could do in a thump without breaking.

 

Super Twin is a smaller cab minus HF driver and gets 133dB ~ max output with 1200w so maybe ~130 with the Terror giving its all.

[Lowend soldier]

On 12/04/2022 at 22:20, T-Bay said:

Oh yes! I have the 1000w version, you wouldn’t let your daughter marry it!

can you tame these beasts or are they purely all gnarl

[CJPJ]

Thanks @Downunderwonder - your technical experitse outstrips mine by some way

 

@Lowend soldier there is a 1000w version for sale here https://www.facebook.com/marketplace/item/5091043320973668/ at a very reasonable price

[T-Bay]

3 hours ago, Lowend soldier said:

can you tame these beasts or are they purely all gnarl

You can indeed, I changed the pre-amp valves to get a bit more clean headroom on mine. With 1000w on tap losing a little top end volume is not a problem.

[Stub Mandrel]

12 hours ago, Lowend soldier said:

can you tame these beasts or are they purely all gnarl

 

The current 500W version has a clean switch. But why would you want to tame oranfe gnarl? 😆

[Lowend soldier]

22 minutes ago, Stub Mandrel said:

 

The current 500W version has a clean switch. But why would you want to tame oranfe gnarl? 😆

disgusting right 🤔😂😂😂. Think i was fingered by a metal fan in my pram 😉😂

[Pan]

hey guys why cant i just set to 4 ohms and just not turn up all the way - 8ohms is only 250 watts through the obc115 , yet its a 400 watt cab : / ??

 

[BassmanPaul]

The 4Ω tap only gives you more power if connected to a 4Ω load. 

[PigBass]

On 12/04/2022 at 21:46, PigBass said:

Hello Pan, I just checked the Orange website and the cab is indeed listed as 8 Ohms as Breadbin mentioned so that’s the setting you should use on the amp.

 

There is a conversation to be had about the fact that the amp can potentially deliver the full 500W into an 8 Ohm load using this setting, and the cab has a max handling limit of 400W. I’d personally not worry so much about this unless you intend to run everything at full volume. Listen to your cab, it will tell you if you’re stressing it. 
 

Cheers, Darren. 

 

EDIT I'll add a post to correct the statement about the impedance switch - I got it wrong

I must have dreamed this. I contacted Orange and a helpful chap called Joe gave me this information:

 

Hi Darren,

 

The impedance switch works more like a limit switch.

The switch is connected to a limiter circuit. When 4 ohms is selected it bypasses an additional resistor, when in 8 ohms the circuit engages this additional 2.2k resistor.

This is to get the most out of your signal when matching impedance.

I don’t believe there to be any difference in this circuit from MK1 and MK2

I hope this is helpful.

 

Kind regards,

Joe

 

 

[Bill Fitzmaurice]

On 12/04/2022 at 16:46, PigBass said:

There is a conversation to be had about the fact that the amp can potentially deliver the full 500W into an 8 Ohm load using this setting, and the cab has a max handling limit of 400W.

The more pertinent conversation is the fact that said 400W rating is thermal. The mechanical limit is perhaps half that. The majority of posters in the thread appear to be unaware of thermal versus mechanical capacity. The good news is that it will sound quite awful if you exceed the mechanical limit.

[CJPJ]

39 minutes ago, Bill Fitzmaurice said:

The majority of posters in the thread appear to be unaware of thermal versus mechanical capacity. 

Totally. I'm just a regular consumer who reads the side of the box and assumes that 1+1=2. If I can't actually get the 500w clean through 2 x 400w cabs and neither the manufacturer nor the retailer is educating me then I'm bound to remain clueless. That said, I wound't know 500w from 400w or 300w it it hit me in the head - I just go by how it sounds in the room or on the day - either it works or it doesn't.